1. Field of the Invention
The invention relates to processes for the hydrofluorination of 2-chloro-3,3,3-trifluoropropene(1233xf) to 2-chloro-1,1,1,2-tetrafluoropropane(244bb).
2. Description of the Related Art
Antimony halides have previously been described as useful as catalysts in the hydrofluorination of 1233xf to 244bb. Antimony pentachloride has been observed to be particularly active in catalyzing the hydrofluorination reaction (as disclosed in U.S. Provisional Patent Application 61/021,121, filed Jan. 22, 2008) but sometimes induces overfluorination of 1233xf to form pentafluoro compounds, such as 1,1,1,2,3-pentafluoropropane(245cb). 245cb has a lower boiling point than the desired 244bb product, which makes it difficult and costly to separate and remove. Antimony pentachloride can still be employed as a catalyst, but a lengthy induction or conditioning period is necessary to allow the catalyst to age.
It would be desirable to have a process for hydrofluorination of 1233xf to 244bb in which the induction period would be substantially reduced or eliminated. It would also be desirable to have a process for hydrofluorination of 1233xf to 244bb with improved yield and selectivity.